[South Florida DX Association] ARLP008 Propagation de K7RA

[Bill Marx]

 SB PROP ARL ARLP008
> ARLP008 Propagation de K7RA
> 
> More zeroes! A string of zero-sunspot days re-appeared this week, a
> pattern we'll likely see repeated over the next year, but for longer
> periods. Average daily sunspot numbers compared to last week dropped
> nearly two points to 7.1. On February 20 and 21 a gust of solar wind
> hit Earth, causing a moderate rise in geomagnetic indices and
> visible aurora way up north. A small coronal hole on our sun's
> equator was the source.
> 
> Over the next week don't expect a rise in sunspot numbers. You can
> take a look at recent numbers, updated daily at,
> http://www.sec.noaa.gov/ftpdir/indices/DSD.txt. Check
> http://www.sec.noaa.gov/ftpdir/indices/DGD.txt for geomagnetic
> indicators.
> 
> A solar wind from a coronal hole is expected to cause unsettled
> conditions for Friday and Saturday, February 24-25.  Geophysical
> Institute Prague expects unsettled conditions for February 24, quiet
> to unsettled on February 25, quiet February 26-27, and quiet to
> unsettled on February 28-March 2.
> 
> We receive a steady stream of mail inquiring about the magnitude of
> the next solar cycle, and the end of this one. Steve Stutman,
> KL7JT/1 in the Boston area said he'd heard somewhere that the rise
> of the next solar cycle should be modest. I poked around, and found
> this interesting link for solar cycle 24:
> http://www.lund.irf.se/rwc/cycle24/.
> 
> With twenty-three recorded sunspot cycles, there isn't a huge amount
> of data to analyze. And so you can see on this site, various
> approaches are put forth, which the users believe have worked in the
> past. I think most of us would prefer Hathaway's prediction, which
> is the first one listed under Predictions of Cycle 24. We would
> prefer it, because it is the most optimistic.
> 
> Don't miss this graphical presentation of data from the current
> cycle 23: http://www.sec.noaa.gov/SolarCycle/. Also, see a nice
> visualization of all recorded solar cycles at
> http://wm7d.net/hamradio/solar/historical.shtml. You can see from
> these graphs why cycle 19 in the late 1950s is recalled with such
> fondness.
> 
> I became interested in ham radio as a young boy in 1963, got my
> license in 1965, and not only was solar activity low during the
> mid-1960s, but cycle 20 peaking in the late sixties was a real
> stinker in comparison to the recent one. Of course all of the older
> hams (just about everyone, since I was 12 at the time) had
> experienced cycle 19, and I hadn't. My only recollection of cycle 19
> was as a small boy in Reedley, California.
> 
> My father was a biologist, taking a few years off to earn money for
> school selling insecticide to farmers before returning to Berkeley
> for his PhD. My dad had a company car, with a long whip antenna on
> the back connected to a low-VHF business-band FM two-way radio
> (probably 30-40 MHz). I recall him talking about being unable to
> raise the head office in Fresno, but someone in Texas was able to
> relay for him, and something about sunspots. Around that time hams
> were living it up on 10-meter AM, working the world with low power.
> 
> We don't have many sunspots now, so the MUF (maximum usable
> frequency) tends to stay low. But we do have quiet conditions, and
> the CQ 160-Meter SSB contest this weekend isn't bothered by low MUF.
> 
> Finally, Cap Cox, W4AMW of Owensboro, Kentucky wrote in about the CW
> portion of the ARRL International DX Contest, which was last
> weekend, and conditions in general:
> 
> "Saturday morning around 1000-1200z I worked Japan, Russia, Western
> Europe and could hear VT and CO all about the same time on 40
> Meters. That night I worked Japan and Switzerland on 80. Sunday
> during the day 20 was open into Europe and Africa all day and even
> 10 Meters lit up into Central and South America in the early
> afternoon. I'm running a hundred watts into a Windom. I kept looking
> at my calendar to make sure it wasn't 2013 already. Wow!"
> 
> Cap goes on to say, "I guess it helps to have a couple of thousand
> operators on all the HF frequencies pushing the ethereal envelope in
> order to know what conditions are really like under the
> circumstances. I can get by with 'poor' bottom of the cycle
> conditions like these for a long time, maybe even until the next
> 'peak' arrives."
> 
> Thanks, Cap.
> 
> If you would like to make a comment or have a tip for our readers,
> email the author at, k7ra at arrl.net.
> 
> For more information concerning radio propagation and an explanation
> of the numbers used in this bulletin see the ARRL Technical
> Information Service propagation page at,
> http://www.arrl.org/tis/info/propagation.html. An archive of past
> propagation bulletins is found at, http://www.arrl.org/w1aw/prop/.
> 
> Sunspot numbers for February 16 through 22 were 27, 23, 0, 0, 0, 0
> and 0 with a mean of 7.1. 10.7 cm flux was 79.2, 79.2, 78.5, 76.5,
> 76.2, 75.9, and 76, with a mean of 77.4. Estimated planetary A
> indices were 8, 4, 2, 6, 20, 17 and 12 with a mean of 9.9. Estimated
> mid-latitude A indices were 7, 2, 2, 5, 9, 15 and 11, with a mean of
> 7.3.
> NNNN
> /EX
> 
>